Re: [PATCH v7 3/7] xen: introduce xen,enhanced dom0less property

[Julien Grall <julien@xxxxxxx>]

Hi Stefano,

On 13/05/2022 22:07, Stefano Stabellini wrote:
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index c4dd211b91..8d148b209d 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -3157,6 +3157,7 @@ static int __init construct_domU(struct domain *d,
>                                    const struct dt_device_node *node)
>   {
>       struct kernel_info kinfo = {};
> +    const char *dom0less_enhanced;
>       int rc;
>       u64 mem;
>   
> @@ -3172,6 +3173,17 @@ static int __init construct_domU(struct domain *d,
>   
>       kinfo.vpl011 = dt_property_read_bool(node, "vpl011");
>   
> +    rc = dt_property_read_string(node, "xen,enhanced", &dom0less_enhanced);
> +    if ( rc == -EILSEQ ||
> +         rc == -ENODATA ||
> +         (rc == 0 && !strcmp(dom0less_enhanced, "enabled")) )
> +    {
> +        if ( hardware_domain )
> +            kinfo.dom0less_enhanced = true;
> +        else
> +            printk("Error: tried to use xen,enhanced without dom0\n");
In general, I prefer if we fail early for configuration error because 
this makes a lot more obvious what the issue is.
So I would switch to panic() and drop "Error:". This can be done on commit:

Acked-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

--
Julien Grall